It is known that some 1,4-dihydropyridine compounds possess coronary artery dilating activity and/or vasodepressor activity.
In fact, however, it is difficult to say that synthesis and pharmaceutical studies of such 1,4-dihydropyridine derivatives have given satisfactory results.
The present inventors made studies with the aim of developing new 1,4-dihydropyridine derivatives which possess very excellent pharmacological activities, in particular potent and long lasting hypotensive activity, coronary vasodilatation, cerebral vasodilatation, peripheral vasodilatation, renal vasodilatation and platelet aggregation inhibitory activity and which are of low toxicity; as a result, the inventors discovered new compounds which possess these activities and which are of low toxicity, and completed the present invention.